Sand glass



FIG. 1 is a perspective view of a sand glass showing my new design;

FIG. 2 is a front elevational view thereof; the opposite side being a mirror image thereof;

FIG. 3 is a left elevational view thereof; the opposite side being a mirror image thereof; and,

FIG. 4 is a top plan view thereof; and the opposite side being a mirror image thereof. 

The ornamental design for a sand glass, as shown and described. 